This invention relates to the separation of water from solutions of organic compounds.
It is known to separate water from organic compounds in more than one step. For example, in some processes, water is separated from an ethanol solution to provide a higher concentration of ethanol than that created by fermentation of sugars in the initial culture and still further water is removed in successive steps.
In the prior art, multiple stage techniques for separating water from an organic material, high quality energy approaches are used to separate large amounts of water in a first step and then smaller amounts of water are separated by other techniques. For example, in one process, most of the water in a solution of alcohol and water formed by fermentation is removed by fractional distillation and the last fraction is removed by using a chemical such as benzine to provide anhydrous ethanol. It is also known to remove the last small traces of moisture by other dehydrating materials such as dehydrating salts and the like.
The prior art methods have the disadvantage of using large amounts of high quality energy to remove most of the water.